From c93bb58102daf231424f75ca7dc92ba3e01ec61e Mon Sep 17 00:00:00 2001
From: chunhtai <47866232+chunhtai@users.noreply.github.com>
Date: Thu, 16 Jul 2020 11:00:28 -0700
Subject: [PATCH] Makes IOS dispatch showOnCcreen action for header semantics
 nodes (flutter/engine#19788)

* Makes IOS dispatchs showOnCcreen action for header semantics nodes

* update

* format
---
 .../ios/framework/Source/SemanticsObject.mm   |  3 +-
 .../framework/Source/SemanticsObjectTest.mm   | 65 ++++++++++++++++++-
 2 files changed, 64 insertions(+), 4 deletions(-)

diff --git a/engine/src/flutter/shell/platform/darwin/ios/framework/Source/SemanticsObject.mm b/engine/src/flutter/shell/platform/darwin/ios/framework/Source/SemanticsObject.mm
index 34694b55175..8819e6374c8 100644
--- a/engine/src/flutter/shell/platform/darwin/ios/framework/Source/SemanticsObject.mm
+++ b/engine/src/flutter/shell/platform/darwin/ios/framework/Source/SemanticsObject.mm
@@ -452,7 +452,8 @@ flutter::SemanticsAction GetSemanticsActionForScrollDirection(
 - (void)accessibilityElementDidBecomeFocused {
   if (![self isAccessibilityBridgeAlive])
     return;
-  if ([self node].HasFlag(flutter::SemanticsFlags::kIsHidden)) {
+  if ([self node].HasFlag(flutter::SemanticsFlags::kIsHidden) ||
+      [self node].HasFlag(flutter::SemanticsFlags::kIsHeader)) {
     [self bridge]->DispatchSemanticsAction([self uid], flutter::SemanticsAction::kShowOnScreen);
   }
   if ([self node].HasAction(flutter::SemanticsAction::kDidGainAccessibilityFocus)) {
diff --git a/engine/src/flutter/shell/platform/darwin/ios/framework/Source/SemanticsObjectTest.mm b/engine/src/flutter/shell/platform/darwin/ios/framework/Source/SemanticsObjectTest.mm
index 7ee7df2d2b7..3c42aeacb3e 100644
--- a/engine/src/flutter/shell/platform/darwin/ios/framework/Source/SemanticsObjectTest.mm
+++ b/engine/src/flutter/shell/platform/darwin/ios/framework/Source/SemanticsObjectTest.mm
@@ -8,16 +8,33 @@ FLUTTER_ASSERT_ARC
 
 namespace flutter {
 namespace {
+
+class SemanticsActionObservation {
+ public:
+  SemanticsActionObservation(int32_t observed_id, SemanticsAction observed_action)
+      : id(observed_id), action(observed_action) {}
+
+  int32_t id;
+  SemanticsAction action;
+};
+
 class MockAccessibilityBridge : public AccessibilityBridgeIos {
  public:
-  MockAccessibilityBridge() { view_ = [[UIView alloc] init]; }
+  MockAccessibilityBridge() : observations({}) { view_ = [[UIView alloc] init]; }
   UIView* view() const override { return view_; }
   UIView<UITextInput>* textInputView() override { return nil; }
-  void DispatchSemanticsAction(int32_t id, SemanticsAction action) override {}
+  void DispatchSemanticsAction(int32_t id, SemanticsAction action) override {
+    SemanticsActionObservation observation(id, action);
+    observations.push_back(observation);
+  }
   void DispatchSemanticsAction(int32_t id,
                                SemanticsAction action,
-                               std::vector<uint8_t> args) override {}
+                               std::vector<uint8_t> args) override {
+    SemanticsActionObservation observation(id, action);
+    observations.push_back(observation);
+  }
   FlutterPlatformViewsController* GetPlatformViewsController() const override { return nil; }
+  std::vector<SemanticsActionObservation> observations;
 
  private:
   UIView* view_;
@@ -102,4 +119,46 @@ class MockAccessibilityBridge : public AccessibilityBridgeIos {
   XCTAssertTrue([object nodeShouldTriggerAnnouncement:&node]);
 }
 
+- (void)testShouldDispatchShowOnScreenActionForHeader {
+  fml::WeakPtrFactory<flutter::MockAccessibilityBridge> factory(
+      new flutter::MockAccessibilityBridge());
+  fml::WeakPtr<flutter::MockAccessibilityBridge> bridge = factory.GetWeakPtr();
+  SemanticsObject* object = [[SemanticsObject alloc] initWithBridge:bridge uid:1];
+
+  // Handle initial setting of node with header.
+  flutter::SemanticsNode node;
+  node.flags = static_cast<int32_t>(flutter::SemanticsFlags::kIsHeader);
+  node.label = "foo";
+
+  [object setSemanticsNode:&node];
+
+  // Simulate accessibility focus.
+  [object accessibilityElementDidBecomeFocused];
+
+  XCTAssertTrue(bridge->observations.size() == 1);
+  XCTAssertTrue(bridge->observations[0].id == 1);
+  XCTAssertTrue(bridge->observations[0].action == flutter::SemanticsAction::kShowOnScreen);
+}
+
+- (void)testShouldDispatchShowOnScreenActionForHidden {
+  fml::WeakPtrFactory<flutter::MockAccessibilityBridge> factory(
+      new flutter::MockAccessibilityBridge());
+  fml::WeakPtr<flutter::MockAccessibilityBridge> bridge = factory.GetWeakPtr();
+  SemanticsObject* object = [[SemanticsObject alloc] initWithBridge:bridge uid:1];
+
+  // Handle initial setting of node with hidden.
+  flutter::SemanticsNode node;
+  node.flags = static_cast<int32_t>(flutter::SemanticsFlags::kIsHidden);
+  node.label = "foo";
+
+  [object setSemanticsNode:&node];
+
+  // Simulate accessibility focus.
+  [object accessibilityElementDidBecomeFocused];
+
+  XCTAssertTrue(bridge->observations.size() == 1);
+  XCTAssertTrue(bridge->observations[0].id == 1);
+  XCTAssertTrue(bridge->observations[0].action == flutter::SemanticsAction::kShowOnScreen);
+}
+
 @end